Semi-erected carton



Jan. 15-, 1963 L M. l. WILLIAMSON 3,

SEMI-ERECTED CARTON Filed March 3. 1959 8 Sheets-Sheet 1 INVENTOR.MARSHALL l. WILLIAMSON ATTORNEYS 73M, ZwMwa/M AMT/ l Jan. .15, 1963 M.WILLIAMSON 3,073,501

SEMI-ERECTED CARTON Filed Mai'ch :s, 1959 8 Sheets-Sheet 2 FIG. 5

INVENTOR.

MARSHALL I. WILLIAMSON Y P ZZ flJ/I/A an .77 0

11 TTORNEYS Jan.'15, 1963 M. I. WILLIAMSON SEMI-ERECTED CARTON 8Sheets-Sheet 3 Filed March 3, 1959 FIG.

INVENTO ,1 MARSHALL I. wp uAMsoN BY Qu -t, a

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ATTORNEYS Jan. 15, 1963 M. WILL'IAMSON SEMI-EERECTED CARTON 8Sheets-Sheet 4 Filed March 3, 1959 FIG. l4

9/? ATTORNEYS INVENTOR MARSHALL I. W| LLI A MSON Jan. 15, 1963 M. I.WILLIAMSON 3,073,

SEMI-ERECTED CARTON Filed March 3, 1959 8 Sheets-Sheet 5 INVENTORMARSHALL l. WILLIAMSON BY WWI- aw ATTORNEYS Jan. 15, 1963 M. l.WILLIAMSON- SEMI-ERECTED CARTON Filed March 3. 1959 8 Sheets-Shet 6INVENTOR MARSHALL I. WILLIAMSON BY FM (M m ATTORNEYS Jan. 15, 1963 M.WILLIAMSON SEMI-ERECTED CARTON 8 Sheets-Sheet 8 Filed March 3, 1959INVENT'OR MARSHALL I. WI LLIAMSON BY wma,-M M 1 vATTORNEYS Patented Jan.15, 1963 3,073,501 SEMI-ERECTED CARTON Marshall I. Williamson, Oradell,N.J., assignor to Federal Paper Board Company, Inc., Bogota, N.J., acorporation of New York Filed Mar. 3, 1959, Ser. No. 796,813 14 Claims.(Cl. 22916) This invention relates to cartons formed of paper board, orrelated sheet stock, of the type having a reclosable cover hinged to abox part and adapted to telescope over the open end of the box part, andhas for its object the provision of an improved carton of this type,particularly a carton having a sealed reclosable cover with releasablelocking means such as the type widely known as the KLIKTOP, and aprocess comprising a sequence of operations or steps in forming thecarton.

The invention provides a semi-erected carton, which is in a state oferection intermediate between the blank state and the filled andcompleted carton. The blank usedin forming the carton consists of asingle sheet of paper board of suitable weight and toughness having cutsand fold lines by means of which it can be formed into a carton havingrectangular sides, ends, bottom and means for forming the cover. Informing the semierected carton of the elevation, the flat blank partlyis glued and folded into a flat position in which state it isdistributed to the user for complete erection filling with goodsandgluing.

It is one of the important features of the invention that in thesemi-erected carton the means on the. cover for effecting the latchingof the. cover to the front panel is attached; as with adhesive, or isotherwise secured or connected, to the front panel of the carton in theposition it occupies in the completed carton.

In one aspect of the invention, the latching means on the cover isformed from a flap which is folded back in the contiguous cover paneland secured in that position to form a reinforced cover panel having aninner abutmentv edge which engages an abutment edge of a hinged abutmentflap on the front panel of a carton. This reinforced part of the coveris secured as by glue or other connection to the front panel of thecarton in the semi-erected state.

In one form of the invention, also, the front panel of the carton has.at least one nearly cut out segment area, and may have a few nearly cutout segment areas, to which the folded back latching flap of the coveris attached by glue. The carton cover is opened by prying it away fromthe front panel which causes the segment area or areas to be torn fromthe front panel and, because they are glued to the folded-back part ofthe cover, they remain there. The segment area or areas may be cutpartly through the thickness of the paper in which case only a layer ofeach segment will be peeled off and retained on the folded-back part. Itis preferred, to print theflat blank and to omit the ink from thesegmentareas so that the glue will stick to them and not to thesurrounding printed surface, but, if desired, spots of glue may beapplied by the glue. wheel. These segment areas preferably-have straightedges which are arranged to be transferred in edge contact and alignmentwith the inner abutment edge of the cover folded back flap.

In a variation of the invention, the folded back portion of the coverclosure or flap. is. omitted and the, inner face of the cover panel isglued directly over the front panel having the cut segment area orareas. These. segment areas are, so nearly completely out out that theybecome attached to the cover and transferred to the front panel of thecover when the cover is opened to provide the closure abutment edges.

In any of the various forms of the invention the prying away of thecover from the front panel, or the front panel from the cover, seversthe connection between them.

The partly erected carton of the invention can be changed from its fiatfolded semi-erected position to a box-like position having the endsopen, either by hand or by machine, and the goods can be insertedthrough either open end. When the carton is filled with merchandise,some of the panels are folded into position, glue is applied to two ofthe opposite end panels and cover flaps, and the end panels and coverflaps are folded into position and glued together. One of the importantfeatures of this invention is that it provides a Kliktop type box thatcan be formed, and completely sealed, including the cover, entirely bymechanical means. The weakly sealed cover closure part canbe openedeasily, by -the user and thereafter opened and closed repeatedly.

These and other novel features of the invention will bebetter understoodafter considering the following discussion taken in conjunction with theaccompanying drawings in which: I I a 1 FIG. 1 is a plan view of a paperboard blank which has been cut and scored for forming a carton of the:invention;

FIG. 2 is a plan view of a semi-erected carton in flat position formedof the blank of FIG. 1;.

FIG. 3 is an end view of the carton of FIG; 2 showing in full lines anintermediate position to illustrate the arrangement-of FIG. 2, and inbroken lines with the front and back panels andthe bottom andcove'rpanels in parallel positions, and with the ends open in the pdsition forfilling with merchandise;

FIG. 4 is a perspective of the top erected carton with parts removed;

FIG. 5 is a sectional view at 5-5 of FIG. 4;

FIG. 6 is a view similar to that of FIG. 4 with the cover open; I 2

FIG. 7 is a cross-sectional view similar to section 5-5 of FIG. 4,. butwith the carton cover partly open;

FIG. 8 is a perspective view of the top portion of a modification of thefully erected carton;

FIG. 9 is a cross-sectional view of FIG. 8, FIG. 5 but with the coveropen;

FIG. 10 is a plan view of a modification of paper board blank which hasbeen out and scored for forming a carton of the invention;

FIG. 11 is a plan view of a semi-erected carton in fiat position formedof the blank of FIG. 10-;

FIG. 12 is an end view of the cartonof FIG. 11. show ing in full linesan intermediate position to illustrate the arrangement of FIG. IL, andin broken lines with the front and back panels and the bottom and coverpanels in parallel positions, and with the ends open in the position forfilling with merchandise;

,7 FIG. 13 is'a perspective of the semi-erected cartoriof FIGS. 11 and12 when filled with merchandise, the inner end panels and flaps foldedinto position and: the projectflaps ready for glue;

portion of the fully similar to ing end panels and the attached 'FIG. 14is a view of the carton of FIG. 13 in the position for application ofglue to the extendingpan'els;

FIG. 15 is a perspective of the completely erectedcar ton. of FIG. 14,after the panels and flaps have been glued into position;

FIG. 16 is a plan view of another modification of paper board blankwhich has been cut and scored for forming a carton of. the invention;

FIG. 17 is a plan position formed'of theblank of FIG. 16;?

FIG. 18 is an end view of the carton of FIG. lTshow ing in r n lines anintermediate position to illustrate the view of a semi erecte'd cartoninfiat arrangement of FIG. 17, and in broken lines with the front and backpanels and the bottom and cover panels in parallel positions, and withthe ends open in the position for filling with merchandise;

FIG. 19 is a perspective view of the semi-erected carton 'of FIGS. 17and 18 ready to be filled with merchandise;

FIG. 20 is a fragmentary perspective view of the carton of FIG. 19 afterfilling and showing the application of glue to one of the panels;

FIG. 21 is a view similar to FIG. 20 showing the application of glue toa flap;

- FIG. 22 is a perspective view of the filled and completely closedcarton.

FIG. 23 is a plan view of still another modification of paper boardblank which has been cut and scored for forming a carton of theinvention;

ing a detail;

FIG. 28 is a perspective view of the filled and completely closedcarton;

FIG. 29 is a further fragmentary perspective view of a detail;

FIG. 30 is a fragmentary view of the upper portion of the carton afterthe initial opening and before reclosing;

FIG. 31 is a fragmentary perspective view illustrating a detail shown inFIG. 30; and

FIG. 32 shows a modification of another detail. The blank shown in FIG.1 is formed of stiff paper board and the face showing will be 'on theinside of the completely erected carton. For reasons which are importantin gluing the panels to minimize warping, the grain of the fibersextends in the lengthwise direction of the blank. The blank has scorelines 1 and 2 with or without interrupted slits, cuts 3, 4, 5, 6, 7 and8, and score lines 9, 10, 11, 12, 13 and 14.

The panel 15 formsthe front of the carton. The flap 17 has an abutmentedge 18 and can assume either the position of FIGS. 4 and 5, or FIGS. 6and 7 when the carton is first completed and before use by the customer.The panels 20 and 21 are integral with panel 15 and form the outer endsof the carton. The panel 22 forms the bottom and the dust flaps 23 and24 are integral with the bottom and are turned upwardly inside thecarton as part of the ends.

The panel 25 forms the back of the carton and has integral panels 26 and27 which are bonded to panels 20 and 21 to form the ends when the cartonis completely erected. The upper ends of panels 26 and 27 have flaps 30and 31 that are bent inwardly to extend over the upper open top of thecarton as shown in FIG. 6 to stiffen the carton during gluing.

The cover structure consists of a central top panel 32 and a dependingfront or latching panel 33 and two end panels 34 and 35 which, whenarranged as in FIGS. 4 to 9, form the telescoping or exterior dependingend portions of the cover. The glue flaps 36 and 37 are folded over andglued to the cover panel 32 as shown in FIGS. 4 and 8. The latching flap38 may be used as in the modifications shown in FIGS. 4 and 5, oromitted as in the modification shown in FIGS. 8 and 9. Flap 38 is foldedover and glued to the panel 33 to provide the inside abutment edge 39 asshown in FIGS. 5, 6 and 7.

The semi-erected carton shown in FIGS. 2 and 3 is formed of the blank ofFIG. 1 by folding the front panel 15 and end panels 20 and 21 on scoreline 12 to overlie panels 22, 23 and 24, and to partly overlie panels25, 26 and 27.

End panels 20 and 21 have their corners cut off diagonally, as shown inFIG. 1, and a glue strip is applied transversely to pass over thetriangles 40, 41 and 42 which are cut in the top of front panel 15. Theentire surfaces of panels 20, 21 and 15 are printed, with the exceptionof the triangular areas 40, 41 and 42, and the glue is eflfective onlyin these areas.

Panels 32, 33, 34 and 35, and glue flaps 36 and 37 are folded alongscore line 10 to overlie the end portion of panel 15, as shown in FIG.2, and panel 33 and flap 38, which has been folded and glued to itsinner surface, are pressed against the glue on triangular areas 40, 41and 42, thereby sealing the carton in its semi-erected position, asshown in FIG. 2. During the application of the glue strip by whichadhesive is placed on the triangular areas 40, 41 and 42, the diagonaledges of the cut-off corners may touch the glue wheel. These edges,however,

'are now masked by panels 34 and 35 so that when the semi-erectedcartons are stacked they will not adhere to one another.

FIG. 3 shows the panels spread apart in full lines for clarity and itwill be noted that the panels and flaps 17, 20, 21, 23, 24, 26, 27, 30,31, 34 and 35 are left in their extended flat positions so that when thecarton assumes the position shown in broken lines the opposite ends areopen.

As shown in FIGS. 2 and 3, the inside surface of flap 38 is glued to thetriangles 40, 41 and 42 in such position that the edges 43, 44 and 45 ofthe triangles are coincident with the aubtment edge 39. This increasesthe thickness of the abutment edge when the cover is opened and thetriangles are transferred to the flap 38 providing a better lockingengagement with the abutment edge 18.

The flap 17 which carries the abutment edge 18 may be left extended asin FIG. 2 in which case it will occupy the inwardly extending positionshown in FIGS. 4, 5 and 8 in the completed carton. In order for thisflap to form a locking engagement with flap 38, so that abutment edges18 and 39 are in locking contact, which is a characteristic of theso-called Kliktop cartons, flap 17 must be bent forward and downward.When the carton is opened by the purchaser, the flap 17 is bentoutwardly in removing the goods to the position shown in FIG. 7 and whenthe cover is closed, the flap is pressed downward to its lockingposition. However, the flap 17 may be bent to this locking positionprior to forming the semi-erected carton of FIGS. 2 and 3.

The blank of FIG. 1 and the semi-erected carton as shown in FIGS. 2 and3 do not have the glue applied on the shaded areas shown when the blankis flat. These areas are shaded to show where the glue will eventuallybe applied. The glue is applied on panels 20, 21, 34, 35 and flaps 36and 37 after the carton has been erected to the position shown in brokenlines in FIG. 3, and filled with merchandise.

As shown in FIG. 3, in full lines, the panels have been displaced fromthe flat semi-erected position merely for clarity of illustration. Thissemi-erected carton may be changed from the flat position to the erectedloading posi tion shown in broken lines in FIG. 3 by applying pressurein the direction of the arrows, and this may be done by a machine. Whenin this erected position, the ends are open for filling and this mayalso be done mechanically. The filled carton with the panels extendingoutwardly is passed through a glue applicator to apply the glue to theareas shown in the shaded areas of FIG. 1 as will be explained in thedescription of FIGS. 13, 14 and 15. The small glued areas on the panels34 and 35 are for sealing these panels to only small areas of panels 26and 27 near the hinge or fold line 10 of the cover. It will be notedthat the corners of panels 20 and 21 are cut off diagonally and thatwhen flaps 34, 35, 36, and 37 are folded over to the position shown inFIG. 2, in which position the glue is applied as shown in FIG. 14, thatpanels 20 and 21 mask the unglued parts of flaps 34 and 35 whereas thediagonal cuts permit the application of glue to the small areas of flaps34 and 35. After the glue has been applied, the glued panels and fiapsare folded and pressed into their glued position shown in FIG. 8 bymechanical means now available.

The customer opens the cover by prying apart the panels 33 and therebytearing the triangles from the panel 15. Then the cover may be limitedin the usual way. The cover can be opened and reclosed repeatedly withabutment reengagement and release at each closing.

The blank of FIG. 1 may omit the flap 38 in which case the inner surfaceof panel 33 is glued directly to the triangles 4t), 41 and 42 whenforming the semi-erected carton of FIGS. 2 and 3. The edges 43, 44 and45 of the triangles become the abutment edge of the cover to engage theabutment edge 18 of the flap 17 as shown in FIGS. 8 and 9.

The blank shown in FIG. 10 is generally similar to the blank of FIG. 1and is formed of similar paper board. The blank has score lines and 51,with or without interrupted cuts, cuts 52, 53, 54, 56, 57, 58 and 59,and score lines 61, 62, 63, 64, and 66.

The panel is the front of the carton, the flap 71 has an abutment edge72 and can be used in the same manner as flap 17 of FIG. 1. The panels73 and 74 are integral with panel 70 and form the outer ends of thecarton. Panel 75 forms the bottom of the carton and the glue flaps 76and 77 are for sealing the bottom edges as shown in FIG. 15. The dustflaps 80 and 81 are integral with bottom 75 and are turned up inside thecarton.

The panel 82 forms the back of the carton and has integral panels 83 and84 which are bonded to panels 73 and 74, respectively, in the completedcarton to form the ends. The small flaps 85 and 86 are folded inwardlyin the completed carton and serve mainly to stiilen the carton duringerection and gluing.

The cover of the carton is formed of the top panel 87, the frontdepending cover panel 88, and panels 89 and 90, glue flaps 92 and 93,and latching flap 94 having an abutment edge 95 which engages theabutment edge 72 in the latching of the cover. The triangles of the formshown in FIGS. 1-9 have been replaced by a single continuous, narrowcut-scored segment area 96 having an edge 97 which functions in relationto the flap 94 and abutment edge 95 in the same manner as thecorresponding parts of FIG. 1.

The glue is applied to the blank in the manner previously described byan applicator which applied a strip transversely across the blank overthe area 96 before panels 87, 88, 89 and 9t} and glue flaps 92 and 93have been folded along score line 62 to the position shown in FIG. 11.At the same time glue may be applied to the inside face of flap 94 (theface shown in FIG. 10). The surfaces of panels 70, 73 and 74 are printedwith the exception of area 96 and it is only the glue on this area thatis etfective as an adhesive.

If desired, the segment area 96 may consist merely of a strip of glue,the cut-scoring being omitted. Such strip of glue will be sufficientlynarrow so that it can be broken by prying apart from the front panel 70of the carton the front cover panel 88 to which flap 94 has been glued.

The semi-erected carton of FIG. 11 is formed by folding flap 94 over oncover panel 88 and then folding panels 76, 71, 73 and 74 along scoreline 64, 180 into contact with panels 82, 83 and 84, thereby gluing flap94 to panel 88 and panel 88 to the segment area 96. Again, should gluehave been received on the edges of the blank by the applicator whichapplied the glue strip over area 96, such undesirably glued portionshave now been masked by the panels 89 and 96. This prevents such gluefrom contacting adjacent blanks or semi-erected cartons when they arestacked. The latching flap 94 may be used or not as in FIG. 1, but whenused it is folded over and glued to the inside. of panel 8 8'. When notused, the front panel 88 becomes glued to the segment area 96. Then thecover panels and flaps are folded along score line 62 to the positionshown in FIG. 11 and the inner face of fiap 94 is pressed into gluedcontact with the segment area 96, securing the carton in itssemi-erected position.

FIG. 12 shows in full lines the carton in a partly opened conditionmerely to illustrate the arrangement of the parts, and in broken lines,to show the position it assumes when mechanically pushed in thedirection of the arrows to the position for mechanically filling withmerchandise through the open ends.

FIG. 13 shows the carton after it has been filled and after the flaps 85and 86 have been turned in, flaps 80 and 81 have been :folded in and thepanels 83 and 34 folded in over them. In this state of erection, thepanels and [flaps 89, 92, 73 and 76 on one end, and the panels and flaps90, 93, '74 and 77 on the opposite end are left extending outwardly intheir original fiat positions of FIG. 11. The panels 73 and 74 partlymask the end panels 89 and 90, the diagonally cut ofi corners leavingparts of these panels exposed for the application of glue by the gluewheels.

FIG. 14 shows a more advanced step in the sequence of operations withthe carton of FIG. 13 being carried on a conveyor 102 with the extendedflaps and panels passing over the glue wheels 103 and 104, to apply glueto the areas for completely sealing the cart-on. In the next mechanicaloperation the panels 73 and 74 are pressed into glued contact withpanels 83 and 84 and 89 and 90, respectively. Then the glue flaps 76 and77 and the glue flaps 9'2 and 93 are bent over and pressed into gluedcontact with the bottom panel 75 and the top panel 87, respectively,thereby completely finishing the carton.

To open the carton, the customer price the front cover panel 88outwardly, breaking the connection of the segment area 96 with the frontpanel 70, and the cover can be lifted open and swung on score line 62 asa hinge. When a strip of glue is used instead of segment area orcut-scored area 96, the prying of cover panel 88 severs such glue strip.When the cover is closed, the abutment edges 72 and 95 function in themanner characteristic of Kliktop cartons.

The sequence of operations informing the carton. of the inventioncomprises the cutting and creasing of the blanks, folding them to formthe semi-erected cartons of FIGS. 2 and 11 with the front part of thecover in glued contact with the front panel, the mechanical spreading ofthe parts as in FIGS. 3 and 12 to arrange the carton in position withopen ends for filling with merchandise, the folding of flaps and panelsfor the sides inwardly while leaving the flaps and panels as in FIG. 13for glue =applioation, the application of glue as in FIG. 14 and thefinal closing of the glue panels and glue flaps to (form the carton ofFIG. 15.

The triangles 40, 41 and 42 of FIG. 2 are a convenient means ofproviding removable glued sections to reinforce or to provide abutmentedges. Other shaped areas may be used which will provide abutment edges,such as rectangles, circles or semicircles.

In FIGS- 16-22 there is illustrated a further modification of thecarton. The blank shown in FIG. 16 is somewhat similar to the blank ofFIG. 1 and is formed of similar paper board. The blank has score lines105 and 106, with or without interrupted cuts, cuts 107, 108, 109, and1-10, and score lines 111, 112, 113, 114, 115,, and 116.

The panel 117 forms the front of the carton. The flap 118 has anabutment edge 119 and can be used in the same manner as. flap 17 ofFIG. 1. The panels 120 and 121 are integral with panel 117. Panel 122forms the bottom of the carton, and dust flaps 123 and 124 which areintegral with the bottom 122 serve to make a tight seal for the bottomedges as. shown in FIG. 21, and will be apparent later on.

. Panel 125 forms the back of the carton and has integral panels 126 and127 which are bonded to panels 120 and 121, respectively, to form theends, 123 and 124 being folded between them, in the completed carton aswill be described. V

The cover of the carton is formed by the top panel.

the dust flaps panel 129, and end panels which are formed by flaps 130and 131 at one end and by flaps 132 and 133 at the opposite end (seeFIG. 22). A latching flap 134 projects from the front cover panel 129and has an abutment edge 135 which engages the abutment edge 119 in thelatching of the cover after the carton has been opened and is thenreclosed by the user, as will be explained later. The segment areas arecutscored circles 136, 137, 138, 139, and 140 and function in relationto the flap 134 and abutment edge 135 in the same manner as thecorresponding parts of FIG. 1.

Glue is applied to the blank as previously described by an applicatorwhich applies a strip transversely across the blank over the fivesegment areas. At the same time, glue may be applied on the inside faceof flap 134 (FIG. The surfaces of panels 117, 120, and 121 are printedwith the exception of the circular areas 136-140, and it is the glue onthese areas only that is effective as an adhesive when the blank isfolded as described below. If desired, a suitably constructed glue wheelmay be used to apply spots of glue, previous printing being thenunnecessary.

The semi-erected carton of FIG. 17 is formed by folding the flat sheetcomprising panels 117, 118, 120, and 121 along score line 114 to overliepanels 122, 123, and 124 and to partially overlie panels 125, 126, and127. Then panels 128, 129, and 134 and flaps 130, 131, 132, and 133 arefolded about score line 112 to overlie the end portion of front panel117 as shown in FIG. 17, panel 134 being previously folded about foldline 105 and glued to the inner surface of panel 129. The outer surfaceof flap 134 is glued to the front panel 117 at the five circular segmentareas 136-140, the glue having been applied to these areas as describedin the previous paragraph. Again should glue have been received on theedges of the blank by the applicator which applied the glue strip overcircular areas 136-140 such undesirably glued edges have now been maskedby the panels 131 and 133. Thus such glued edges are prevented fromcontacting adjacent blanks or semi-erected cartons when they arestacked.

As with the forms shown in FIGS. 2-3 and 11-12, the semi-erected cartonsof FIGS. l7.and 18 are shipped to the user in the flat and partlypre-sealed condition shown, and the user completes the erection of thecartons as illustrated in FIGS. 19-22. During this operation he fillsthe cartons with his product. Both the erection and closing of thecarton, and the insertion or loading of the product can be carried outon suitably modified conventional machines.

After squaring up a carton as illustrated in FIG. 18 and as describedpreviously in connection with the other forms of the invention, thepanels and flaps at its opposite ends are manipulated to close and sealthe carton in substantially the following sequence:

Panel 120 (FIGS. 19 and 21) is folded to closed position and panels 121and 127 are spread slightly. Then the load is inserted between theseflaps and against the previously folded panel 120 at the opposite end.There after, the folding of the remaining panels and fiaps at both ends,and the application of glue to certain of these flaps, takes placesimultaneously, and a description of such folding at the right hand endonly will be given.

Panel 121 is first folded downward to vertical position against the loadand dust flap 124 is folded inwardly, that is, to the right over panel121. Next flap 132 is folded outwardly to the position of FIG. 20 andflap 133 is folded upwardly to the position shown in this figure, afterwhich glue is applied to the inner surface of panel 127. As indicated inFIG. 20, this may be done by passing this panel while supporting it inhorizontal position, beneath a glue roll 141 indicated in dot and dashlines. After this glue application, panel 127 is folded to the verticalposition (FIG. 21) and sealed against the surface of inner panel 121 anddust flap 124 A 128, the front depending dust proof seal is thus made atthe bottom of the carton.

Flap 133 is now swung to horizontal position, flap 132 being held in itsoutwardly extended position and passed between a pair of glue applyingrolls 142 which apply glue to both surfaces of flap 133. The outersurface of panel 127 is printed except for a segment area 143 which isshown as being circular, and flap 133 is folded downwardly against thesurface of panel 127 so that the glue on the inner surface of the flapadheres to the circular area 143. The folding of fiap 132 over flap 133now completes the operation, the glue on the outer surface of the flapcausing them to adhere to one another. The compltion of the sealingoperation at the opposite end of the carton has been finishedsimultaneously, as previously referred to, and sealing pressure isapplied by conventional means to the two opposite ends only of thecarton.

The flap 118 will usually be left in the position shown in FIGS. 17 and18 but if desired may be folded so that its abutment edge 119 isadjacent abutment edge 135 of flap 134 when the carton is in itssemi-erected condition as shipped by the carton manufacturer. When thecarton is filled with flap 118 extending upwardly as shown in FIGS. 17and 18, the customer opens the carton by prying the front cover panel129 outwardly so as to sever the segment areas, such as 138, 139, andshown in FIG. 22, and also pries open the two end cover panels, severingthe single segment area 143 at each end. The cover may then be swungopen on score line 112 as a hinge. Before re-closing, the customerswings latching flap 118 outwardly so that the closing of the cover willturn it downwardly to latching position with abutmerit edge 135 on theinside of the front cover panel.

Consideration will now be given to FIGS. 23-32 where a still furthermodification of the carton is illustrated. An important feature of thismodification is to provide a car-ton in which no out edge of the blankshows at the front of the carton. Another important feature is the factthat in closing the carton only one glue wheel or glue-applying roll isrequired at each end of the carton. A third feature is the use of aplurality of short locking tabs or flaps instead of a single long tab.

The blank of FIG. 23, the inner face being shown, is somewhat similar tothe blanks of FIGS. 1, 10 and 16 and is formed of similar paper board.This blank has a score line 144, with or without interrupted cuts, and adiscontinuous 0r sectional score line 145, and also score lines 146,147, 148, 149, and 151. Panel 152 forms the front of the carton.Projecting from the edge of this panel are two spaced locking flaps 153,each having an abutment edge 154. These flaps can be used in the samemanner as the single locking fiap 17 of FIG. 8 and flap 113 of FIG. 17.Also the single locking flap may be used on the blank of FIG. 23, ifdesired. Locking flaps 153 are spaced apart leaving a central spacebetween them the material of which is added at the opposite end of theblank, as will be presently described.

The panels 155 and 156 are integral with front panel 152. Panel 157forms the bottom of the carton and sealing flaps 158 and 159 areintegral with the bottom 157 and serve to make a tight seal for thebottom edges, as shown in FIG. 29 and as will be apparent later on.

Panel 160 forms the back of the carton and has integral panels 161 and162 which are to be bonded to panels 155 and 156 respectively to formthe ends of the carton, the sealing flaps 158 and 159 being foldedbetween them in the completed carton, as will be described.

The cover of the carton is formed by the top panel 163, the frontdepending panel or extension 164 and end flanges which are formed bycurved sealing flap 165 and rectangular flap 166 at one end and bycurved sealing flap 167 and rectangular fiap 168 at the opposite end(see FIGS. 23 and 30). A flap 169 projects from front cover panel 164,but because of the provision of the two spaced 9 locking flaps 153 ithas two abutment edges 176' which are properly located to be engaged bythe latching flaps 153 in the latching of the cover when the filledcarton is opened and reclcsed by the user.

The central portion of flapv 169 between the abutment edges 170 iswidened by the addition to the blank of the material on the next blankcorresponding to the central space previously referred to between thetwo latching flaps 153. This is advantageous as it renders fiap 169easier to fold along the score line 144. Should single locking flaps beused, such for example as flap 118 in FIG. 16, flap 169 will not bewidened at its central portion and a single abutment edge in line withedges 170 will be used.

The segment areas are cut-scored circles 171, 172 and 173 and functionin relation to the flap 169 and abutment edge 170 in the same manner asthe corresponding parts of FIGS. 1 and 17. It will be understood thatany suitable number of these segment areas may be used, and

also that the single segment area or strip, as shown at 96 in FIG. 11,or the triangular segment areas, shown in any of the previous figuresmay be used, if desired.

Although for the blank shown in FIG. 23 no illustra tion correspondingto FIGS. 2, 11 and 17 has been included, it will be understood that inits semi-erected and fiat condition the blank of FIG. 23 is folded in amanner similar to that shown in those figures and particularly FIG. 17.That is to say, glue is applied to the fiat blank of FIG. 23 in the.same way as it is to the blanks shown in FIGS. 1, l and 16, that is, byan applicator which applies a strip or glue transversely over thesegment areas.

At the same time that glue is applied over the segment areas 171-173 itmay also be applied on the inner or top face of flap 169. The surfacesof panels, 152, 155 and 156 are printed with the exception of thecircular areas 171173, and it is the glue on these areas only that iseffective as an adhesive. If desired a suitably constructed glue wheelmay be used for the purpose of applying spots of glue at the locationsof the circular areas 171-173, and in that case prior printing of theblank is unnecessary.

The folding of the blank of FIG. 23 to form a semierected carton in flatcondition, as shown in FIG. 17, for example, is carried out by foldingthe. flat sheet comprising panels 152, 153, 155 and 156 along score line149 through about 180 to overlie panel 157 and extended flaps 158 and159', and to partially overlie panels 160, 161 and 162. The panels 163-and 164V and extended flaps 165, 166, 167 and 168 are folded about scoreline 147 to overlie the end portion of front panel 152 in a mannersimilar toy that shown in FIG. 17, panel 169 having been previouslyfolded about fold line 144 and glued to the inner surface of panel 164.The outer surface of flap 169 is glued to the front panel 152 at thethree circular segment areas 171-173, the glue having been applied tothese areas, as described in the preceding paragraph.

The cartons are shipped to the user in the flat and partly pre-sealedcondition just described, the same as in the case of the forms of theinvention shown in FIGS. 2 and 3, 11, l2, l7 and 18, and the usercompletes the erection of the cartons, as illustrated in FIGS. 24 to 28.During this operation he fills the carton With his product. Both theerection and closing of the carton and the loading of the product can becarried out on suitably modified conventional machines.

After squaring up a carton in the same manner as indicated in FIG. 18and as described previously in connection with the other forms of theinvention, the panels and flaps at the opposite ends of the carton aremanipulated to close and. seal it in substantially the followingsequence:

Panel 161 at the left (FIG. 24) is folded upwardly to closed. position,and the load is insertedbetween panels 156and 162 at the opposite endand against the 16 folded panel 161. After this the folding of theremain ing. panels and flaps at both ends of the carton and theapplication of glue take place simultaneously at both ends of thecarton, and a description thereof more particularly for the right-hand.end, will be given.

Panel 162 is first folded upwardly to vertical position against theload. Inasmuch as the flap 159 and curved flap 167 project in the planesof their respective panels 157 and 163 difiiculty has been experiencedthrough the engagement of the end portions of panel 162 with the edgesof these two flaps. This difiiculty has now been avoided by concavingtheend edges of flap 162 (and also flap 161) at the opposite end asindicated at 178. Flaps 159 and 167 are. next folded inwardly. Thepresence of the square edges 159a on flaps 158 and 159 (FIG. 23) isadvantageous in providing stability and in maintaining the box in squarecondition. Glue is applied to the inner surface of panel. 156 and to aportion of the inner surface of flap 168 while both of these membersremain in extended position. This may be done by passing this flap andpanel over a glue roll 174 (FIG. 26).

The top corner portions of panels 155 and 156 have been cut away, aswere the corners of the corresponding panels 20 and. 21 of FIG. 1,73'and 74 of FIG. 10, and and 121 of FIG. 16, and for a similar purpose.When the glue is applied to the segment areas 171-173 (blank upfolded asin FIG. 23), as previously described, any glue received on the edges ofthe blank by touching the glue wheel is masked when cover end flaps 166and 168 are folded thereover to the semi-erected positions of FIG. 2, 11or 17, and this prevents such glue from contacting similar blanks instacked relation.

However, the corners of panels and 156 are cut away in a special mannerhaving additional advantages. These corners have a somewhat differentconfiguration. As shown in FIG. 23 the corners of these two flaps arecut away on a 45 line 176 for about one third of the. panel width,thence along a steeper, or curved, line to a small notch or shoulder176a, and then continuing to the panel edge in a straight edge 175 atright angles to the outside edge of the panel.

Each of the rectangular cover end flaps 166 and 168 which, with sealingflaps and 167 form the end flanges of the cover, may be provided with asmall projection in the form of a lobe or ear a (FIG. 23). These lobesserve the important purpose of controlling and maintaining correctposition and alignment of flaps 1 66, 168 with respect to the panels155, 156 and with the top panel 163 of the cover in the final sealing ofthe carton as now will be described.

With the carton traveling on the machine in the di rection of the arrow(FIG. 24) the lobes 175a support the fiaps 166 and 168 in the horizontalplane of the extending panels 155 and 156.. As the cartons travelcontinues the panel 155 and flap 166 at one end, and panel 156 and flap168 at the other end, pass over sup porting rails (not' shown). Justafter the flaps 166, 168 pass beyond the ends of such rails suitablydesigned plows (or other mechanisms) sharply depress the flaps 166 and'168 so that they snap past their respective points of lobe support. Theedges of the lobes, particularly their outer edges, are shaped as camsto facili+ tate this action.

Having left the plow-s or other flap depressing mechanism in thiscondition, the carton next passes between glue rolls, one of which isshown at 174 (FIG. 26), which apply adhesive, as previously mentioned,to the exposed underside areas of the flaps 166 and 168 not maskedby theuncut-away areas of the panels 155 and .156, and to the entire remainingunderside area-s of these panels With adhesive thus applied, the flaps166 and 168 and the panels 155 and 156 are plowed downwardly in unisonagainst the previously up-folded. panels 161 and 162 11 and thethereover in-folded sealing flaps 165, 167 and 158, 159 respectively.The flaps 166, 168 are thus bonded to the sealing flaps 165, 167respectively, but are not bonded to the surrounding exposed areas of theunderlying panels 161, 162 which areas have been printed to prevent suchbonding.

It is in the course of this downward plowing (FIG. 27) and bonding ofthe flaps 166, 168 and panels 155, 156 that the lobes 175a perform theirimportant function of controlling and maintaining correct position andtrue alignment of the lower edges of these flaps by abutment with theupper straight edge portions 175 of these panels. Were it not for theedge-to-edge abutment maintained by these lobes, the drag of the foldingplows and of the pressure section of the machine would cause varyingunsightly and inoperative mis-alignment of the flaps 166, 168 with theedges 175 of the respective panels 155, 156 and with the top panel 163of the cover of the finished carton.

Also, since the cover end fiaps 166, 168 are not bonded at any point tothe panels 161, 162, their lower edges would be free to flare outwardlywere it not for the lobes 175a which, despite no adhesive, hold thelower edges of these flaps neatly, firmly and close to the rear cornersof the carton, yet leaving the sides of the assembled cover otherwiseun-secured and free to open when the front seal (spots 171-173) of thecover is broken. The cover can be tilted upwardly as shown in FIG. 30without hindrance from the lobes 175a. Upon reclosure of the: coverthese lobes will remain on the exterior surfaces of the respective endsof the carton.

Since the cover end flaps 166, 168 are engaged by the plows in advanceof the panels 155-156 it is desirable to transmit the folding motion ofthe flaps to the panels. This is done, for example, by the pressure offlap 168 against the shoulder 176a and the triangular area of panel 156beneath this flap (FIG. 25), by which a positive downward motion to thepanel 156 is effected. FIG. 25 shows flap 168 raised to expose thetriangular area mentioned. If desired, however, this notch 176a may beomitted and the outline of the cut-away portion of the panel made asshown in the modified form of FIG. 32. In this form the 45 line 176joins a steeper line 177 the outer end of which connects with thestraight right-angled edge 175.

Another feature of the present construction is the cutting of shortangular slits 180, 181, 182 and 183 in panels 161 and 162. These slitsextend inwardly from the bases of panels 161 and 162 (FIG. 23), that is,from the respective fold lines 150 and 151. This places one of the slitsnear each corner of rear panel 160. The purpose of these slits is toobtain tight joints at both the bottom and top of the box, and theyfunction as follows:

Slit 181 is at the top of the box (FIGS. 26 and 30) and slit 183 at thebottom (FIG. 26). When flap 168 and panel 156 are folded downwardlyafter having received the glue on their undersurfaces, they are pressedagainst the surfaces of the respective curved flaps 167 and 159 whichhave previously been folded inwardly against panel 1152. The presence ofthe slits permits the lower ends of flaps 167 and 159 to be pressedinwardly to a slight extent flexing the material of panel 162 in contactwith these flaps and thereby bringing the outer surfaces of the lowerends of these flaps into the same plane as the outer surface of panel162 on the opposite sides of and adjacent the respective slits 181 and183.

This is best shown in FIG. 29 where flap 159 has been folded upwardlyagainst the outer surface of the end portion of panel 162. Flap 159 isshown in the position it will occupy after panel 156 has been folded toclosed position. That is to say, the outer surface of the right endportion 184 of this flap is shown in the sarne plane as the narrowportion 185 of panel 162 between slit 183 and the corner of the box.

In order to facilitate cooperation of the flaps with the slits, each ofthese four flaps 158, 159, 165 and 167 advantageously is formed with astraight edge 186 at least as long as the length of the adjacent slit.This prevents the possibility of the edge of the flap depressing thearea of the panel on the opposite side of the slit such, for example, asarea 185 in FIG. 29. The angle of the edges 186 of flaps 158, 159, 165and 167 with respect to fold lines and 151 (FIGS. 23 and 29) may bevaried as desired, but advantageously these edges are placed at about 45to the fold lines. The angle of the slits 180-183 with respect to foldlines 150 and 151 is made slightly less than the angle of the edges 186in order to reduce or eliminate the possibility of edges 186 overlappingtheir adjacent slits and overlapping onto areas 185.

The two short latching flaps 153 (FIG. 30) are shown bent outwardly sothat when the cover is reclosed by the user they will be foldeddownwardly to provide the latching engagement between these abutmentedges 154 and the abutment edges 170 of folded flap 169 which extendsalong the front panel of the cover. It will be understood that latchingflaps 153 may, when the carton is in its semi-erected state, extendupwardly in a position corresponding to flap 17 of FIG. 2 or to flap 71of FIG. 12.

An important feature of the present invention which is common to all ofthe embodiments described above is that of the cut-away corners of theend-sealing panels (see panels 20 and 21 of FIG. 1, 73 and 74 of FIG.11, 120 and 121 of FIG. 16 and 155 and 156 of FIG. 23). This feature hasimportant advantages both in the manufacture of the semi-erected cartonand in the subsequent formation or erection of the box and the sealingthereof.

In the manufacture of the carton it enables the use of high speedstraight line gluing of the glue seam, that is, the attachment betweenthe folded portions of the semi-erected carton, so that this operationcan be performed on standard equipment. Without these cut-away areas atthe corners the blanks would have to be timeglued, which would reducethe speed of gluing by about one-half, in order to avoid the applicationof glue to exposed areas that would cause the blanks to stick togetherunder pressure, as when stacked.

Furthermore, in most cases the cut-away corners enable the glue to beapplied, in the sealing of the filled box, in one pass over a singleglue wheel at each side of the carton, so as to bond not only the boxend sealing flags, but also just the desired limited areas of the coverend flaps where this is intended.

Heretofore, in the manufacture of KLIKTOP boxes special equipment hasbeen required in the formation of the cover portions, and even thenthese cover portions were incapable of being sealed. However, by thepresent invention both the formation and the sealing of such cartons isaccomplished by the use of standard and existing manufacturing andsealing equipment, thus simplifying and reducing the cost of cartons ofthis type.

I claim:

1. A carton formed of a single blank having rectangular panels forforming the front, back, end and bottom walls, and a cover panel hingedto the back panel, sealing flap extensions on at least one of saidbottom and cover panels, the end panels projecting from the front andback walls and being foldable to form the ends of the carton, the panelsprojecting from the back wall being folded to form the inner layers ofthe end walls, the bottom sealing flaps being folded thereover and thepanels projecting from the front carton wall being folded over both thebottom sealing flaps and the inner layer and being glued thereto, thepanels forming said respective inner layers each having an angularlydisposed slit therein extending respectively from at least two of therear corners of the carton, and the sealing flaps at said corners eachhaving an edge portion positioned adjacent one side of 13 each of saidslits, the glued surface of the outer end wall panel contacting thesurface of one of said sealing flaps and the surface of said inner panelin the same plane thereby forming a tight corner joint.

2. A carton acording to claim 1 wherein the slits are of the order ofone-half inch in length and disposed at an angle of about 45 with therear wall of the carton.

3. A carton blank according to claim 1 wherein the sealing flaps at therear corners of the carton each have a straight edge portion disposedadjacent the slit in the inner layer.

4. A carton formed of a single blank rectangular panels for forming thefront, back, end and bottom walls, and a cover panel hinged to the backpanel and having a cover front-forming extension and cover end-formingmembers extending therefrom which telescope over the front and endpanels of the carton When the carton is erected, sealing flap extensionson said cover and bottom panels, the end panels projecting from thefront and back Walls being foldable to form the ends of the carton, thepanels projecting from the back wall being folded to form the innerlayers of the end walls, the bottom sealing flaps being folded thereoverand the panels projecting from the front carton Wall being folded overboth the bottom sealing flaps and the respective inner layers and beingglued thereto, characterized by the fact that the opposite edges of thepanels projecting from the back wall are made in concave shape so thatin folding these panels they will not engage the edges of the unfoldedsealing flaps.

5. A carton formed from a blank having ractanglar panel member forforming the front, back, end and bottom walls, and a cover panel hingedto the back panel, the end panel members projecting from the front andback walls and being foldable to form the ends of the carton with thepanel members projecting from the back wall forming the inner layer ofthe end walls, the cover panel having a front-forming extension andcover endforming members extending therefrom arranged to telescope thefront and ends of the carton when the cover is in closed position, thecover end-forming members and the panel members projecting from thefront wall being foldable to form respectively the outer layer of theend walls and the cover ends, sections of the adjacent edges of thesetwo members at each end of the carton being positioned in abuttingrelationship, and projecting means on one of said abutting membersengaging the opposite member so as to prevent misalignment of saidabutting members during folding to form the completely erected carton.

6. A carton blank according to claim 5 wherein the projecting means isin the form of an ear and projects from the lower outer corner of eachof the cover end members, said ears, in the filled and closed carton,underlying the adjacent marginal edge portion of each of the outer endwall members.

7. A carton blank according to claim 6 wherein the projecting means isin the form of an ear having a sloping cam edge to facilitate theshifting of the ear to the inner surface of the panel member projectingfrom the front wall.

8. A carton blank according to claim 5 wherein the projecting means isin the form of an ear projecting from one of the abutting members.

9. A carton blank according to claim 8 wherein the ear is provided witha sloping cam edge to facilitate the shifting of the ear to the oppositesurface of the cooperating abutting member.

10. A carton formed from a blank'having rectangular panel members forforming the front, back, end and bottom walls, and a cover panel hingedto the back panel,

the end panel members projecting from the front and back walls and beingfoldable to form the ends of the carton with the panel membersprojecting from the back wall forming the inner layer of the end walls,the cover panel having a front portion and end members arranged totelescope the front and ends of the carton when the cover is in closedposition, the cover end members and the panel members projecting fromthe front wall being foldable to form respectively the outer layer ofthe end walls and the cover ends, sections of the adjacent edges ofthesetwo members at each end of the carton being positioned in abuttingrelationship, projecting means adjacent the lower corner of one of saidabutting members to prevent misalignment of the abutting members duringfolding to form the completely erected carton, and projecting meansdisposed on the panel member which forms the outer layer of the endwall, such projecting means being engaged with the inner surface of the'cover and flap so that folding pressure applied to such flap will alsoserve to fold the panel member forming the outer layer.

11. A carton formed of a single blank having rectangular panels forforming the front, back, end and bottom walls, and a cover panel hingedto the back panel and having a cover front-forming extension and coverendforming members extending therefrom which telescope over the frontand end panels of the carton when the carton is erected, sealing flapextensions on said cover and bottom panels, the end panels projectingfrom the front and back walls being foldable to form the ends of thecarton, the panels projecting from the back wall being folded to formthe inner layers of the end walls, the bottom sealing flaps being foldedthereover and the end panels projecting from the front carton wallforming the outer layers of the end walls and being folded over both thebottom sealing flaps and the respective inner layers and being gluedthereto, characterized by the fact that the top outer corners of the endpanels projecting from the front wall of the carton are cut away so thatportions thereof will lie in edge-abutting relationship with portions ofthe cover end-forming members.

12. A carton formed of a single blank having rectangular panels forforming the front, back, end and bottom walls, and a cover panel hingedto the back panel and having a cover front-forming extension and coverendforming members extending therefrom which telescope over the frontand end panels of the carton when the carton is erected, sealing flapextensions on said cover and bottom panels, the end panels projectingfrom the front and back walls being foldable to form the ends of thecarton, the panels projecting from the back wall being folded to formthe inner layers of the end walls, the bottom sealing flaps being foldedthereover and the end panels projecting from the front carton wallforming the outer layers of the end walls and being folded over both thebottom sealing flaps and the respective inner layers and being gluedthereto, characterized by the fact that each end wall outer layer is cutaway to form an upper edge appreciably below the top of the carton, andthat such exterior cover end-forming member has a Width as measured fromthe top in the direction of the bottom whereby the edge thereof makesedge-abutting engagement with the upper edge of the outer end wall.

13. A carton formed of a single blank having rectangular panelsforforming the front, back, end and bottom walls, and a cover panel hingedto the back panel and having a cover front-forming extension and coverendfor-ming members extending therefrom which telescope over the frontand end panels of the carton when the carton is erected, sealing flapextensions on said cover and bottom panels, the end panels projectingfrom the front and back walls being foldable to form the ends of thecarton, the panels projecting from the back wall being folded to formthe inner layers of the end walls, the bottom sealing flaps being foldedthereover and the end panels projecting from the front carton wallforming the outer layers of the end Walls and being folded over both thebottom sealing flaps and the respective inner layers and being gluedthereto, characterized by the fact that the 15 contour of the cut-awayportions of the end panels projecting from the front wall of the cartonis such that the forward edges thereof coincide substantially with theforward edges of the cover end sealing flaps so that the edges of thesemembers do not overlap when the carton is fully erected.

14. A carton formed of a single blank having rectangular panels forforming the front, back, end and bottom walls, and a cover panel hingedto the back panel and having a cover front-forming extension and coverendforming members extending therefrom which telescope over the frontand end panels of the carton when the carton is erected, sealing flapextensions on said cover and bottom panels, the end panels projectingfrom the front and back walls being foldable to form the ends of thecarton, the panels projecting from the back wall being folded to formthe inner layers of the end walls, the bottom sealing flaps being foldedthereover and the end panels projecting from the front carton wallforming the outer layers of the end walls and being folded over both thebottom sealing flaps and the respective inner layers and being gluedthereto, characterized by the fact that the top outer corners of thepanels projecting from the front wall of the carton are cut away so thatportions of the under surface of the cover end-forming members whichcorrespond approximately in area with that of the cover end sealingflaps will be exposed for the application of glue simultaneously withthe under surface of the uncutaway portions of said panels whereby thecover endforming members may be brought into adhesive bond with thecover end sealing flaps in closing and sealing the ends of the fullyerected carton.

References Cited in the file of this patent UNITED STATES PATENTS2,015,413 Snyder Sept. 24, 1935 2,280,904 Erekson Apr. 28, 19422,403,698 Williamson July 9, 1946 2,441,445 Ringler May 11, 19482,649,239 Ellsworth Aug. 18, 1953 2,651,450 Ellsworth Sept. 8, 19532,701,091 Sullivan Feb. 1, 1955 2,828,060 Brown Mar. 25, 1958 2,963,214Leone Dec. 6, 1960 FOREIGN PATENTS 585,606 Great Britain Feb. 13, 1947 IUNITED STATESIPATENTI OFFICE I CERTIFICATE OF CORRECTION Patent No; 3073,5Ol

January 15, 1963 i I Marshall I. Williamson I It is hereby certifiedthat error appears in the above numbered patent requiring correction andthat thesaid Letters Patent shouldread as corrected below. I

column 12, flaps for "upfolded" line 48, for "flags" read column 13,line l2 after "blank" line 32, for "mem insert having her" read memberscolumn 14 line 15., for "and" read end Column 1, line 25, for"elevation" read invention column 5, line 7 for "limited" read liftedcolumn 8, line l3 for "compltion" read completion column 9, line 81, for"or read of column 10, line 27 read unfolded 1 Signed and sealed this27th day of August 1963.

(SEAL) Attest:

ERNEST w. SWIDER DAVID LADD Attesting ()fficer Commissioner of Patents

1. A CARTON FORMED OF A SINGLE BLANK HAVING RECTANGULAR PANELS FORFORMING THE FRONT, BACK, END AND BOTTOM WALLS, AND A COVER PANEL HINGEDTO THE BACK PANEL, SEALING FLAP EXTENSIONS ON AT LEAST ONE OF SAIDBOTTOM AND COVER PANELS, THE END PANELS PROJECTING FROM THE FRONT ANDBACK WALLS AND BEING FOLDABLE TO FORM THE ENDS OF THE CARTON, THE PANELSPROJECTING FROM THE BACK WALL BEING FOLDED TO FORM THE INNER LAYERS OFTHE END WALLS, THE BOTTOM SEALING FLAPS BEING FOLDED THEREOVER AND THEPANELS PROJECTING FROM THE FRONT CARTON WALL BEING FOLDED OVER BOTH THEBOTTOM SEALING FLAPS AND THE INNER LAYER AND BEING GLUED THERETO, THEPANELS FORMING SAID RESPECTIVE INNER LAYERS EACH HAVING AN ANGULARLYDISPOSED SLIT THEREIN EXTENDING RESPECTIVELY FROM AT LEAST TWO OF THEREAR CORNERS OF THE CARTON, AND THE SEALING FLAPS AT SAID CORNERS EACHHAVING AN EDGE PORTION POSITIONED ADJACENT ONE SIDE OF EACH OF SAIDSLITS, THE GLUED SURFACE OF THE OUTER END WALL PANEL CONTACTING THESURFACE OF ONE OF SAID SEALING FLAPS AND THE SURFACE OF SAID INNER PANELIN THE SAME PLANE THEREBY FORMING A TIGHT CORNER JOINT.